Re: SCSI Kernel Problem - BAD

Alan Cox (
Tue, 12 Mar 1996 10:45:57 +0000 (GMT)

> problem is more severe when the I/O rate is high. not the amount of data
> as much as the number of I/O operations per second. In a PC, these are
> typically directly related to interrupts. I also noticed that a busy NFS
> connection will aggravate it even more. and I just saw that when NFS was
> busy on these partitions, I was loosing interrupts on the wd.c driver.

Heavy NFS load significantly increases the probability of GFP_ATOMIC or
GFP_DMA memory allocations failing. There are also other things that will
start to happen at this load (clustering attempts fail, the request queue is
full, buffer cache grow/shrink). Is it worth trying these one at a time -
eg a 4 item request queue and seeing if you can break it.